Means for testing underground strata for the fluid content thereof



1, 1942- L. A. DOUGLAS 2,303,727

MEANS FOR TESTING UNDERGROUND STRATA FOR THE FLUID coumws THEREOF FiledJune 10. 1941 2 sheets-sheet 1 E Dec. 1, 1942. L. A. DOUGLAS MEANS FORTESTING UNDERGROUND STRATA FOR THE FLUID' CONTENTS THEREOF Filed June10,-1941 2 Sheets-Sheet 2 Patented Eco. 3, i942 MaANsroR 'rns'rrnes'rae'ra roR 'rnn rt.

THEREOF ERGROUND CONTENT Leslie A. Douglas, San Antonio, Tex.

Application June 10, 1941, Serial No. 397,505

11 Claims.

The primary object of the present invention is to provide eficient meansfor penetrating oil well strata at any desired depth, and to withdrawtherefrom the pore content of the strata so that it may be brought tothe surface of the ground for examination.

I am aware of the fact that devices have heretofore been proposed,adapted to be projected laterally into the material of subterraneanstrata and to bodily withdraw a portion of said strata for purposes ofexamination. The present invention differs radically from these formerlylinown structures, in that it is not concerned with the Withdrawal of acore of solid material containing a very small amount of gases orfluids, but, upon the contrary, aims to withdraw the gaseous and iiuidcontent from a volume of solid material which would be many times thatwhich could be withdrawn in a core tube.

Further objects and advantages will be set forth in the detaileddescription which follows:

In the accompanying drawings: s

Fig. 1 is a vertical sectional view of the device of the invention;

Fig. 2 is an enlarged vertical sectional view through a portion of thestructure of Fig. 1, upon line 22 of Fig. 1;

Fig. 3 is an end view of the core tube;

Fig. 4 is a transverse section taken upon line 6-5 of Fig. 2; and,

Fig. 5 is a side view of the guide barrel shown in section in Fig. 2.

Fig. 6 is a view partly in side elevation and partly in section of amodified form of the invention; v

Fig. 7 is a detailed view of the explosive charge carrying elementhereinafter described, and;

Fig. 8 is a plan view of the tool showing one of the actuating links forthe same in section, on line 88 of Fig. 6.

Like numerals designate corresponding parts type may be mounted upon thereceptacle 5, said receptacle constituting the vacuum chamberhereinafter referred to.

A shut-off valve 7 is located in an air hose connection 8 and byattaching a suction pump to said connection, the air may be exhaustedfrom the receptacle 5 at the surface of the ground. The vacuum chamberand the parts connected thereto may be lowered into the well to betested by a cable, a drill stem or a drill pipe, a drill pipe beingindicatedat 9, and being connectedto the receptacle 5 by a coupling W.

A pipe section I! having its lower end closed by a bull plug i2, isconnected to the receptacle 5 by coupling I3. The chamber formed withinthe pipe section it is laterally spanned by a guide barrel l6. 'Aplunger 15 is slidably disposed in this guide barrel and is adapted tobe forcibly impelled outwardly therefrom by an explosive charge l6. i'Ihe explosive charge may be fired in any suitable; way, as, forexample, by an electrical cap ll supplied with current from the surfacethrough a conductor I8.

The guide barrel H5 is carried by a head block l9, said block beingsecured by bolts lS to the pipe section or cylinder l i. In loading thestructure the plunger i5 is forced under considerable pressure towardthe explosive charge and is then held in place by any suitable number ofshear pins 20, saidpins being adapted to shear off as preferablydownwardly inclined at' about an throughout the several figures of thedrawings.

Broadly stated, the invention comprises the combination of a vacuumreceptacle adapted to be lowered into a bare hole or well, havingassociated therewith meansfor laterally piercing the subterranean strataso that the liquid and gaseous content of the pierced strata may bedrawn under the action of the vacuum into said receptacle.

Referring now to the drawings, 5 designates a preferably cylindricalbody, from which the air is exhausted by any suitable means before thedevice is lowered into the well to be tested. A suitable recordingpressure gauge 6 of a conventional angle of twenty-five degrees (25).The-forward end of the tube 23 is initially closed with a thin brassplate 2Q, said plate being weakened by,

begin to flow into the vacuum chamber Sand continue over such period of.me as the lite not, be left in place or untif. the vacuum is satisfied.This how may be accentuated by any external pressure existent in thestrata.

it is not the object of the present invention to withdraw sand or othersolid materia1 and I may, if desired, provide a coarse screen 29 in thetube to prevent the entry of sand orlik material to said tube.

The lower outer end of guide barrel I l projects into a vertical slot 30formed in the side wall of pipe section II. By referring to Fig. 5, itwill be seen that the guide barrel is made in two parts. In other words,its lower forward portion I4 is separate from and hingedly connected tothe main portion of the barrel by hinges 3 I.

A guide screw 32 is screwed into the plunger i5 and its head travels ina shallow guide groove 33 formed in the lower portion of the uide barrel. The guide barrel is provided with an upper longitudinal slot 36 inwhich the nipple extension 35 of plunger l5 may travel, this nippleextension constituting the point of attachment for tube 25. The guidebarrel is also provided with a lower slot 36 in which the shank of thescrew 32 travels.

An apron 37 is engaged with and moves with the plunger l5. The functionof this apron is to impact mud as the core tube is shot out into thestrata, the greater density of the mud thus brought about tending toprevent flow of the mud into the core tube.

The arrangement shown and described is such that if, because of thenature of the strata, the core tube penetrates the same to such anextent that it cannot be withdrawn and retrieved, it may be abandonedwithout necessitating the loss of the whole tool. To this end, theconnection of the lower end of the tube 2b, with nipple 35 is such thatthe connection may be broken at that point by a strong pull. It will beunderstood that because of the existence of the slots 38 and 3B, thecore tub-e may be shot entirely out of the guide barrel and into thestrata to be tested. The screw 32 will shear oif when this takes place.

Where the nature of the subsoil is such that the core tube is stoppedbefore the plunger completely leaves the guide barrel, the plunger maybe retrieved by drawing upwardly upon the whole tool. In this case thehinged section M swings downwardly upon its hinge and permits themovement of the outer end of th core tube back into the pipe ll by adownward swinging movement through the opening 3i]. A rubber band orcord Ht may be employed to hold the section it closed during the outwardmovement of the core tube. The screw 32 will shear this cord or band offto free the section it.

In the form of the invention illustrated in Figs. 6 to 8, pre createdair pressure, i. e., air pressure stored in the tool before it islowered into the well, is utilized to forcibly project a collecting toolinto the strata. Here a vacuum chamber 50 is secured by a coupling 5! toan air pressure receptacle 52. This receptacle is, in turn, connected toa pipe section 53, and 53 is connected by a coupling 5 5 with a secondair pressure receptacle 55.

The pipe section 53 carries a pair of cylinders 56 and 5'! in whichpistons 5t and 59 are mounted. The piston rods 68 are connected bytoggle links it a tool 52 similar to the tool 23 in that it c n; risesthe body 52, sealing disc or plate 26, scree i nd W tool is connectedasoavav by flexible tube 53 with the vacuum chamber Eli and has anupwardly opening check; vane in its length.

A small box-like receptacle S5 in each of the air pressure receptaclesreceives an explosive which, when electrically fired from the surface ofthe ground through current supplied by wires 61, discharges a lead plug68 from over the mouth of the corresponding pipes 59 to permit the airpressure to pass into the cylinders to and 51 and to there act upon thepistons to thrust the tool outwardly through the open side of pipesection 53.

The rear end of the tool is provided with a guide rod 10 which slidablyengages a guide H.

The pistons carry pins I2 which are embraced by a spring 13. When thepistons have travelled toward each other far enough to uncover the ports14, the air pressure is relieved and the spring 13 may act to retractthe tool.

These ports are designedly made very minute so that the escape of theair will be so slow that the tool will remain in its projected positionthe necessary length ortime.

This structure is a-practical one for withdrawing the oil and gascontent of the strata instead of withdrawing the solid material as hasheretofore been done. As far as I am aware, I am the first to do this.

Many ways will readily suggest themselves to those skilled in the artfor accomplishing the same result. Therefore, I wish it to be understoodthat the invention includes within its purview whatever changes fairlycome within either the terms or the spirit of the appended claims.

1. A testing tube for oil wells comprising a vacuum chamber having avacuum performed therein, a barrel adapted to receive an explosivecharge, an element adapted to be impelled along said barrel by theaction of said explosive charge, means for firing the explosive chargefrom the surface of the ground, a. tubular core tool carried by saidelement adapted to penetrate the strata to be tested under the action orthe explosive charge, means for maintaining connection between thevacuum chamber and the core tool throughout the travel of the core tube,so that the liquid and gaseous pore content of the strata may flowthrough said tool to the vacuum chamher and means rupturable by theentry of the core tool into the strata to be tested which holds thevacuum until the seal is ruptured, an apron having an outwardly flaringinner wall, said apron extending around the core tool and serving toimpact mud around the rear portion of the core tool and means rupturableby the entry of the core tool into the strata to be tested, which holdsthe vacuum until the seal is ruptured.

2. A tool of the character described, comprising a vacuum chamber, apipe section depending therebelow, a guide barrel extending across theipe section, a tubular core tool mounted to move endwise in said guidebarrel, means for impelling said core tool forcibly along the guidebarrel, and a flexible tube connectingthe core tooliand the vacuumchamber.

3. Alstructure as recited in claim 2 wherein said guide barrel isprovided with a hinged, downwardly swinging lower outer end portion.

4. A structure as recited in claim 2 wherein the guide barrel isprovided with a longitudinally extending slot through which saidflexible tube moves.

5. A tool or the character described, comprisins; a vacuum chamber, arecording gauge therein, a pipe section screwed to the lower portion ofthe vacuum chamber and having a. vertical slot formed in its side wall,a bull plug at the lower end of the pipe section, a guide barrelspanning the pipe section and inclined downwardly from the rear to thefront wall thereof,

a plunger in the guide barrel, a tubular core tool carried by theplunger, said guide barrel having a slot therealong and said plungerhaving a nipple which travels in said slot, a flexible tubeconnecting'said nipple and vacuum chamber, a check valve between thenipple and vacuum chamber which opens toward the vacuum chamber, andmeans for creating pressure in the rear of the plunger as and for thepurposes set forth.

6. A structure as recited in claim 5 wherein the pressure creating meanscomprises a body of explosive material and means for firing the same.

7. A structure as recited in claim 5 in combination with a disc havingweakened portions, said disc initially closing the outer end of the coretool.

8. A structure as recited in claim 5 in combination with a disc havingweakened portions, said disc initially closing the outer end of the coretool, and a screen spanning the core tool inwardly of said disc.

9. A tool comprising a receptacle containing air under pressure, achamber of preformed vacuum, a strata penetrating tool, a flexibleconnection between the strata penetrating tool and the vacuum chamber,air operated means for projecting the tool and means for releasing theair from the air pressure receptacle to operate the actuating means ofsaid tool.

10. A tool comprising a receptacle containing air under pressure, acollection chamber, a strata penetrating tool, a tubular connectionbetween the strata penetrating tool and the collection chamber whichprovides a fluid conduit between them throughout the movement of thestrata penetrating tool, air operated means for projecting the tool andmeans for releasing the air from the air pressure receptacle to operatethe actuating means of said tool.

11. A structure as recited in claim 10, wherein the air operated meanscomprises a pair of opposed cylinders and pistons and toggle linksbetween the pistons and the tool.

LESLIE A. DOUGLAS.

